Mechanical behavior and texture development of over-aged and solution treated Al-Cu-Mg alloy during multi-directional forging

Abstract

The effects of initial heat treatments, i.e. solution treating and over ageing, on deformation behavior of an age hardenable Al-Cu-Mg alloy, including mechanical properties and texture evolution, during multi-directional forging (MDF) are investigated. Hardness measurements, electron back scatter diffraction (EBSD) maps, and differential scanning calorimetry (DSC) are carried out. Mechanical behaviors of the alloy in terms of compressive stress and hardness test after MDF are investigated. In both solution treated and over-aged alloys, the compressive stress during MDF shows an increase up to the second pass, and by further straining the flow stress is decreased. However, shear and deformation bands are formed in both solution treated and over-aged alloys, the density of these instabilities in the solution treated alloy is higher than that in over-aged alloy. In the solution treated alloy, not only large particles induce deformation bands, but also the dynamically formed GPB zones/Cu-Mg co-clusters. Texture analysis shows that the shear component of C {001}〈110〉 (Φ1=90°, Φ=0°, Φ2=45°) is developed with 18mrd during MDF of the over-aged alloy. In the solution treated alloy, due to the high density of deformation bands and different microchemistry of the matrix in comparison with that of the over-aged alloy, the Copper type texture component {112}〈111〉 (Φ1=90°, Φ=35°, Φ2=45°) is developed with 11mrd.